NASA Technical Reports Server (NTRS) 20090040757: Applications for Subvocal Speech

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by  NASA Technical Reports Server (NTRS)

similar orthogonal-polarization charac- are used to make and break connections than 4°at 14 GHz. At the time of this re-
teristics, including high degrees of po- toeight microstrip delay lines having dif- porting, this is the first package flexible
larization purity. The diagonal orienta- ferent lengths (e.g., 1 wavelength versus organic RF MEMS multibit phase shifter
tion helps in realizing a symmetrical 3/4 wavelength). Necessarily omitting ever documented.
feed network for both polarizations details for the sake of brevity, each This work was done by Dane Thompson,
with similar impedance characteristics MEMS switch includes a microscopic Ramanan Bairavasubramanian, Guoan
and radiation patterns. RF MEMS flexible electrically conductive member Wang, Nickolas D. Kingsley, Ioannis Papa-
switches would be included in a produc- that, through application of a suitably polymerou, Emmanouil M. Tenteris, Gerald
tion model but are not included in the large DC bias voltage, can be pulled into DeJean, and RongLin Li of Georgia Institute
prototype: Instead, to simplify compu- proximity with microstrip conductors on ofTechnology for Glenn Research Center.
tational simulation and testing, switch- opposite sides of the gap. The flexible Further information is contained in a TSP
ing of polarizations is represented by member is covered to prevent direct (see page 1).
the presence of hard-wired open and electrical contact with the microstrip Inquiries concerning rights for the commer-
short circuits at switch locations. conductors, but the effect of the proxim- cial use of this invention should be addressed
Figure 2 is a plan view of a switchable ity is such as to enable substantial capac- to NASA Glenn Research Center, Innovative
phase shifter — in this case, one that can itive coupling of the microwave signal Partnerships Office, Attn: Steve Fedor, Mail
be switched between two different phase across the gap. The measured loss of the Stop 4–8, 21000 Brookpark Road, Cleve-
shifts. The device includes electrostati- four-bit packaged phase shifter is only land, Ohio 44135. Refer to LEW-17980-1.
cally actuated RF MEMS switches that 0.24 dB per bit with a phase error less
Applications for Subvocal Speech
Ames Research Center,Moffett Field, California
A research and development effort tion of the sub-vocal EMG signals that secret communications among law-en-
now underway is directed toward the represent specific original words or forcement officers and militaryperson-
use of subvocal speech for communica- phrases; transformation (including en- nel in combat and other confronta-
tion in settings in which (1) acoustic coding and/or enciphering) of the sig- tional situations.
noise could interfere excessively with nals into forms that are less vulnerable This work was done by Charles Jorgensen
ordinary vocal communication and/or to distortion, degradation, and/or in- of Ames Research Center and Bradley
(2) acoustic silence or secrecy of com- terception; and reconstruction of the Betts of Computer Sciences Corporation.
munication is required. By “subvocal original words or phrases at the receiv- This invention is owned by NASA and a
speech” is meant sub-audible elec- ing end of a communication link. Po- patent application has been filed. Inquiries
tromyographic (EMG) signals, associ- tential applications include ordinary concerning rights for the commercial use of
ated with speech, that are acquired verbal communications among haz- this invention should be addressed to the
from the surface of the larynx and lin- ardous-material-cleanup workers in Ames Technology Partnerships Division at
gual areas of the throat. Topics ad- protective suits, workers in noisy envi- [phone]. Refer to ARC-15519-1.
dressed in this effort include recogni- ronments, divers, and firefighters, and
Multiloop Rapid-Rise/Rapid Fall High-Voltage Power Supply
Marshall Space Flight Center, Alabama
A proposed multiloop power supply article, there was no commercially avail- back loops would be used to regulate
would generate a potential as high as 1.25 able power supply capable of satisfying the the high output voltage. A pulse trans-
kV with rise and fall times <100 µs. This stated combination of voltage, rise-time, former would be used to turn on four
power supply would, moreover, be pro- and fall-time requirements. FETs to short-circuit output capacitors
grammable to generate output potentials The power supply would include a when the outputs of the PWM were dis-
from 20 to 1,250 V and would be capable preregulator that would be used to pro- abled. Application of a 0-to-5-V square
of supplying a current of at least 300 µA at gram a voltage 1/30 of the desired out- to a PWM shut-down pin would cause a
1,250 V. This power supply is intended to put voltage. By means of a circuit that 20-to-1,250-V square wave to appear at
be a means of electronic shuttering of a would include a pulse-width modulator the output.
microchannel plate that would be used to (PWM), two voltage doublers, and a This work was done by Douglas Bearden of
intensify the output of a charge-coupled- transformer having two primary and two Marshall Space Flight Center.
device imager to obtain exposure times as secondary windings, the preregulator This invention is owned by NASA, and a
short as 1 ms. The basic design of this output voltage would be amplified by a patent application has been filed. For further
power supply could also be adapted to factor of 30. A resistor would limit the information, contact Sammy Nabors, MSFC
other applications in which high voltages current by controlling a drive voltage Commercialization Assistance Lead, at
and high slew rates are needed. At the applied to field-effect transistors (FETs) [email protected]. Refer to MFS-
time of reporting the information for this during turn-on of the PWM. Two feed- 32137-1.
NASA Tech Briefs, January 2007 15